Machine and method for forming collapsible tubing



April 1953 c. E. RUTHERFORD MACHINE AND METHOD FOR FORMING COLLAPSIBLETUBING Filed April 11, 1949 2 SHEETS-SHEET l filll'llfo r:- C Earle-515.Rulifcerf if M April 28, 1953 c. E. RUTHERFORD MACHINE AND METHOD FORFORMING COLLAPSIBLE TUBING Filed April 11, 1949 2 SHEETSSHEET 2 JrutrofoCECLrZeSER Patented Apr. 28, 1953 MACHINE AND METHOD FOR FORMINGCOLLAPSIBLE TUBING Charles E. Rutherford, West Hartford, Conn, as-

Signor to The -Wircmold Company, Hartford, Coma, a corporation ofConnecticut Application April 11, 1949, Serial No. 86,635

13 Claims. 1

This invention relates to collapsible tubing formed of two elements andalso to methods and machines for making such tubing.

It is an object of this invention to provide an improved form of twoelement collapsible tubing in whichthe flexible element is madeand-assembled so that it tends to fold outwardly when the tubing iscollapsed, thus not to impede the flow of air or fluid through thetubing.

Another object of this invention to provide a method for forming theimproved tubing.

Another object of the invention is to provide an improved machine forforming the new tubing.

Another object is to provide improvements and attachments adaptable toknown collapsible tubing machines for producing the new tubing.

Other objects and advantages of the invention will become apparent as itis described in connection with the accompanying drawings.

In the drawings:

Fig. l is a fragmentary perspective View partly in section of theportion of the machine which embodies the invention for making theimproved tubing;

Fig. 2 is an extension of Fig. 1 illustrating the entrance of the fabricguide;

Fig. 3 is a plan view partly broken away and partly in section of themachine shown in Fig. .1;

Fig. 4 is a plan view of the fabric guide showing its relation to thefirst and second convolutions of the spiralled channelled metal member;

Figs. 5-8are transverse section'views of the fabricguide, taken alonglines .55 to .88 of Fig.4.

This inventionis an improvement on tubing, machine and method disclosedin the application of -A..E. Chernack, S. N. 705,539, filed October23,1946, for Methodand Machine for, Forming Tubing, now Patent. No.2,539,814.

Referring to the drawings a strip of thin sheet metal 20 whichpreferably is formed by any suitable means into channel shape by havingits opposite edges bent into acute angles to form flanges 2| and 22 isfed to a rotating mandrel (designated generally by 36) and to a rotarypinching or pressure roll (designated generally by. numeral 50) andbeing guided in an advancing spiral path by a guideway it in a guideblock 49, as will hereinafter be more particularly described.

Thecylindrical mandrel 313 isformed on a rotatingshaft 28 extendingthrough theguide block 4! The mandrelfill also extends through the guideblock 43 and is held in place on the. rotatingshaft 28by means ofa key(notshown) and holtd l soas to. rotatewith the shaft 28,.

The guide block it is a machined casting mounted upon a stationarycasting 4 3 which may in turn be mounted upon a suitable machine frame,not shown. The guide block 40 has -a spiral guideway 42 rectangular incross section cut into its vertical face around and'adjacent the mandrel32! to receive the trailing edge 22 of the preformed channel strip 20.The pitch of the guideway depends upon the desired advance of thechannel strip 20. Secured to the guideblock [it and substantiallyco-extensive with the vertical surface 49a thereof, is a guide or camplate 45, also curved to a spiral shape and positioned so as to engagethe body portion of the metallic strip. The guide plate cooperates withthe spiral guideway 42 in forming the metal strip into a spiral of thedesired pitch by bending the metal strip to closely fit the curvature ofthe mandrel. The guide or cam plate 45 may be secured to the guide block40 by means of screws such as 46.

To guide the opposite side of the channel strip 20, a spiral guidingmember or rib 35 is affixed at one end by a screw upon an extension 44of the guide block as, the surface of the extension being horizontal andsubstantially tangential to the top of the mandrel 30. The guide rib 35winds about one and one-quarter turns around the mandrel and terminatesat that point. Its terminal end is not attached to the mandrel. Themandrel rotates within the guide rib 35.

In order to insert a strip FS of cloth or fabric or other limp flexiblematerial i. e. lacking stiffness, fabric guide means is providedcomprising an upper guide member H3 and a lower guide member 15. Theguide means is fixedly positioned above the mandrel by supportingbracket '12 which may be attached to a fixed part (not shown) of themachine. The upper member it of the cloth guide is generally of invertedchannel form converging at its exit end portion over the top of themandrel as will be described. It may also be curved upwardly toward theentrance end. At the entrance end it has side flanges H, substantiallyperpendicular to the roof of the guide and extending downwardly. As theupper guide member proceeds toward the exit end it converges and theflanges are bent inwardly towards each other into acute angles or curvedreversely toward the mandrel so as to tuckthe fabric under the forwardedge of the first convolution of the metal strip and under the trailingedge of the second convolution. The tucking inof the fabric strip FSunder the forward edge of the first convolution occurs at about thepoint or just prior to the point where the metal strip enters the spiralguideway 42 of the guide block 40.

In order to form an outwardly extending ridge or crimp in the center ofthe fabric strip PS the upper cloth guide member Hi is fluted orprovided with a progressively-deepening downwardly-faced groove 14, theguide being formed into an upwardly and outwardly pressed ridge for thatpurpose and being greatest at the exit of the guide. The groove startsat a point near the entrance of the upper cloth guide on the center linethereof and progressively grows deeper.

Cooperating with the upper fabric guide It is a lower fabric guidemember 16 formed as a strip of metal dimensioned to fit within the upperfabric guide 10 and having its top surface complementary to the innersurface of the upper guide. Thus a rib or ridge TI on the upper surfaceof the lower guide 16 presses the fabric into the groove 14 of the topguide 10 forming a crease or upwardly pointed crimp C along the centerline of the fabric strip FS as it moves along and issues from theguides. The lower guide 16 may terminate short of the end of the upperguide member 10 and may also be short of the entrance end.

With the cloth inserted under the forward edge or flange of the firstconvolution and under the trailing edge or flange of the secondconvolution, the mandrel rotates these elements of the tubing to presentthem to a pressure or pinching roll 59. The pinching roll 50 is mountedupon a rotary shaft 68 and held thereon by a nut 49. The shaft 68 isparallel to the axis of the mandrel.

The driving means for the mandrel and the mounting and driving means forthe pinching roll are omitted from the drawing for clearness. Thosefeatures being known to those skilled in the art and per so not beingpart of the invention, need not be illustrated. Preferably the shaftupon which the pinching roll is mounted is pressed by spring pressure ina known manner (not herein illustrated) so as to cause the pinching rollto press against the tubing with the desired pressure as the roll actsupon the tubing.

The pinching roll is provided with pinching flanges SI, 52 extendingfrom opposite sides of the roll beyond the periphery of the roll, theflanges being spaced so as to straddle the guide rib 35. The flange 5|presses upon the fabric overlying the forward edge of the firstconvolution of the metal strip and the flange 52 presses upon the fabricoverlying the trailing edge of the second convolution of the metal stripso that both of these edges are pressed down simultaneously tofrictionally and securely hold the edges of the fabric strip FS underthese flanges. The peripheral surfaces of the flanges 5!, 52 may andpreferably do incline slightly inwardly as shown in Fig. 3.

During the formation of the tubing this crease H in the fabric isuntouched since it passes between the flanges 5l 52 of the pinching rollwhile the side edges of the fabric strip are secured beneath the edgesof the metal channel strip. As a result of the formation of the crimp inthe tubing the fabric tends to move outwardly as the tube is collapsed.In this way the inward moving of the fabric as in prior collapsibletubing is avoided.

Tubing made according to this invention is claimed in my co-pendingapplication Serial No,

193,250 filed October 31, 1950 which is a division hereof.

From the foregoing it may be observed that I have provided apparatus andmeans for forming collapsible tubing wherein the tubing is formed by thepressure of a single pinching or pressure roll and also the tubing isformed so as to cause the fabric to tend to move upwardly as the tubingis collapsed. It will be apparent to those skilled in the art that othermeans for making crease or crimp in the fabric may be employed and othermeans for bending the edges of the metallic strip upon the edges of thefabric strip may be used. Therefore I do not limit the invention to thespecific embodiment illustrated in the drawings.

What is claimed is:

1. In a machine for forming collapsible twoelement tubing from a stripof limp material and a metal strip preformed into channel shape andhaving its edges bent to form flanges, a rotating mandrel, means toguide said channel strip around the mandrel in a spiral path, means toinsert the edges of the limp strip under different flanges of adjacentconvolutions of the metal strip simultaneously, and means to bend downthe flanges simultaneously onto the inserted limp strip edges to securethem to the metal strip and to connect adjacent convolutions of themetal strip.

2. In a machine for forming collapsible twoelement tubing from a stripof limp material and a metal strip preformed into channel shape andhaving its edges bent to form flanges, a ro tating mandrel, means toguide said channel strip around the mandrel in a spiral path and tospace one convolution from another, means to insert the trailing edgesof the limp strip under the forward flange of one convolution of themetal strip and the forward edge of the limp strip under the trailingflange of a spaced adjacent convolution of the metal stripsimultaneously, and means to bend down the flanges simultaneously ontothe inserted limp strip edges to secure them to the metal strip and toconnect adjacent convolutions of the metal strip.

3. A machine as claimed in claim 1 wherein the bending means comprises apressure roller having peripheral radially extending flangessimultaneously engaging the flanges of the metal strip.

4. A machine as claimed in claim 2 wherein the bending means comprises apressure roller having peripheral radially-extending flangessimultaneously engaging the flanges of the metal strip.

5. In a machine for forming collapsible twoelement tubing from a stripof limp material and a metal strip preformed into channel shape byhaving its edges bent to form flanges, means to secure the edges of thelimp strip under the edges of the metal strip to form continuous tubing,means to feed the limp strip to the channel-form metal strip, and meansassociated with said feeding means to crease the limp striplongitudinally and outwardly of the tubing, said creasing meanscomprising stationary top and bottom guide members between which thelimp strip passes, said members having complementary formations causinga crease to be formed in the limp strip as it passes between said guidemembers to cause the limp strip to fold outwardly when the tubingcollapses.

6. A machine as claimed in claim 5 wherein said reasing means comprisesa top guide mom'- her and a bottom guide member between which theflexible strip passes, said members having complementary formationscausing the crease to be formed in the flexible strip as it passesbetween said guide members, and wherein said top guide member has itsedges bent to guide the edges of the limp strip and insert them underthe flanges of the metal strip.

7. A machine as claimed in claim 5 wherein the top guide member has alongitudinal groove progressively deepening toward the exit end, and thebottom guide member is formed complementary to the top guide member tocause the longitudinal outward crease in the limp strip as it passesbetween the guide members.

8. A machine as claimed in claim 5 wherein said top guide member has itsedges bent to guide the edges of the limp strip and insert them underthe flanges of the metal strip.

9. A machine as claimed in claim 5 wherein said top guide member hasdepending side portions inclined towards each other at the exit end toguide the edges of the limp strip and insert them under the flanges ofthe metal strip.

10. A machine as claimed in claim 9 wherein the top guide member has alongitudinal groove progressively deepening toward the exit end, and thebottom guide member is formed complementary to the top guide member tocause a longitudinal crease in the limp strip as it passes between theguide members.

11. The method of making collapsible tubing comprising forming aspiralled convolution from a preformed strip of metal having its edgesbent to form flanges, forming a longitudinal crease in a limp stripprior to its presentation to the metal strip, forming two convolutionsof said metal strip and spacing them apart, inserting the trailing edgeof a limp strip under the forward flange of one convolution of the metalstrip and simultaneously inserting the forward edge of the limp stripunder the trailing flange of an adjacent convolution of the metal stripand bending down said flanges to secure together the metal and limpstrips.

12. The method of making collapsible tubing comprising forming aspiralled convolution from a preformed strip of metal having its edgesbent to form flanges, forming a longitudinal crease in a limp stripprior to its presentation to the metal strip, forming two convolutionsof said metal strip and spacing them apart, inserting the trailing edgeof a limp strip under the forward flange of one convolution of the metalstrip and simultaneously inserting the forward edge of the limp stripunder the trailing flange of an adjacent convolution of the metal strip,and simultaneously bending down said flanges to secure the metal andlimp strips in adjacent convolutions.

13. A machine as claimed in claim 2 having means associated with saidinserting means to crease the limp strip longitudinally and outward- 1yto cause the limp strip to fold outwardly when the tubing collapses.

C. E. RUTHERFORD.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 809,561 Greenfield Jan. 9, 1906 1,238,987 Colby Sept. 4, 19171,410,160 Brinkman Mar. 21, 1922 1,502,052 Naylor July 22, 19241,661,835 Keller Mar. 6, 1928 2,049,100 Baker July 28, 1936 2,069,052Webb Jan. 26, 1937 2,195,751 Nichols et a1. Apr. 2, 1940 2,234,450Quarnstrom Mar. 11, 1941 2,337,374 Chernack Dec. 21, 1943 2,340,794Chernack Feb. 1, 1944

